package cn.stdlib;
/*************************************************************************
 *  Compilation:  javac Stopwatch.java
 *
 *
 *************************************************************************/

/**
 * <i>Stopwatch</i>. This class is a data type for measuring
 * the running time (wall clock) of a program.
 * <p/>
 * For additional documentation, see
 * <a href="http://introcs.cs.princeton.edu/32class">Section 3.2</a> of
 * <i>Introduction to Programming in Java: An Interdisciplinary Approach</i>
 * by Robert Sedgewick and Kevin Wayne.
 */


public class Stopwatch {

    private final long start;

    /**
     * Create a stopwatch object.
     */
    public Stopwatch() {
        start = System.currentTimeMillis();
    }


    /**
     * Return elapsed time (in seconds) since this object was created.
     */
    public double elapsedTime() {
        long now = System.currentTimeMillis();
        return (now - start) / 1000;
    }

} 
